[Xen-changelog] [xen-unstable] x86: Remove clocksource=tsc for now.

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1216380409 -3600
# Node ID 7f766b4a170b3eda8bd8803d058a26c5746a561d
# Parent  b896b39470f0e1c957c82db30d915875b00c3776
x86: Remove clocksource=tsc for now.
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
 xen/arch/x86/domain.c |    4 ---
 xen/arch/x86/time.c   |   56 ++------------------------------------------------
 2 files changed, 3 insertions(+), 57 deletions(-)

diff -r b896b39470f0 -r 7f766b4a170b xen/arch/x86/domain.c
--- a/xen/arch/x86/domain.c     Fri Jul 18 11:24:13 2008 +0100
+++ b/xen/arch/x86/domain.c     Fri Jul 18 12:26:49 2008 +0100
@@ -286,10 +286,6 @@ int vcpu_initialise(struct vcpu *v)
 
     v->arch.flags = TF_kernel_mode;
 
-    /* Ensure that update_vcpu_system_time() fires at least once. */
-    if ( !is_idle_domain(d) )
-        vcpu_info(v, time).tsc_timestamp = ~0ull;
-
 #if defined(__i386__)
     mapcache_vcpu_init(v);
 #endif
diff -r b896b39470f0 -r 7f766b4a170b xen/arch/x86/time.c
--- a/xen/arch/x86/time.c       Fri Jul 18 11:24:13 2008 +0100
+++ b/xen/arch/x86/time.c       Fri Jul 18 12:26:49 2008 +0100
@@ -481,46 +481,6 @@ static int init_pmtimer(struct platform_
 }
 
 /************************************************************
- * PLATFORM TIMER 5: TSC
- */
-
-#define platform_timer_is_tsc() (!strcmp(plt_src.name, "TSC"))
-static u64 tsc_freq;
-
-static u64 read_tsc_count(void)
-{
-    u64 tsc;
-    rdtscll(tsc);
-    return tsc;
-}
-
-static int init_tsctimer(struct platform_timesource *pts)
-{
-    unsigned int cpu;
-
-    /*
-     * TODO: evaluate stability of TSC here, return 0 if not stable.
-     * For now we assume all TSCs are synchronised and hence can all share
-     * CPU 0's calibration values.
-     */
-    for_each_cpu ( cpu )
-    {
-        if ( cpu == 0 )
-            continue;
-        memcpy(&per_cpu(cpu_time, cpu),
-               &per_cpu(cpu_time, 0),
-               sizeof(struct cpu_time));
-    }
-
-    pts->name = "TSC";
-    pts->frequency = tsc_freq;
-    pts->read_counter = read_tsc_count;
-    pts->counter_bits = 64;
-
-    return 1;
-}
-
-/************************************************************
  * GENERIC PLATFORM TIMER INFRASTRUCTURE
  */
 
@@ -605,8 +565,6 @@ static void init_platform_timer(void)
             rc = init_cyclone(pts);
         else if ( !strcmp(opt_clocksource, "acpi") )
             rc = init_pmtimer(pts);
-        else if ( !strcmp(opt_clocksource, "tsc") )
-            rc = init_tsctimer(pts);
 
         if ( rc <= 0 )
             printk("WARNING: %s clocksource '%s'.\n",
@@ -822,10 +780,6 @@ int cpu_frequency_change(u64 freq)
     struct cpu_time *t = &this_cpu(cpu_time);
     u64 curr_tsc;
 
-    /* Nothing to do if TSC is platform timer. Assume it is constant-rate. */
-    if ( platform_timer_is_tsc() )
-        return 0;
-
     /* Sanity check: CPU frequency allegedly dropping below 1MHz? */
     if ( freq < 1000000u )
     {
@@ -1024,12 +978,9 @@ void init_percpu_time(void)
     unsigned long flags;
     s_time_t now;
 
-    if ( platform_timer_is_tsc() )
-        return;
-
     local_irq_save(flags);
     rdtscll(t->local_tsc_stamp);
-    now = read_platform_stime();
+    now = !plt_src.read_counter ? 0 : read_platform_stime();
     local_irq_restore(flags);
 
     t->stime_master_stamp = now;
@@ -1047,10 +998,10 @@ int __init init_xen_time(void)
 
     local_irq_disable();
 
+    init_percpu_time();
+
     stime_platform_stamp = 0;
     init_platform_timer();
-
-    init_percpu_time();
 
     /* check if TSC is invariant during deep C state
        this is a new feature introduced by Nehalem*/
@@ -1068,7 +1019,6 @@ void __init early_time_init(void)
 {
     u64 tmp = init_pit_and_calibrate_tsc();
 
-    tsc_freq = tmp;
     set_time_scale(&this_cpu(cpu_time).tsc_scale, tmp);
 
     do_div(tmp, 1000);

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